| 摘要 |
A disk drive has a microprocessor, a digital controller chip, and an analog power chip, and a multi-winding spindle motor. The power chip operates under gross and fine control to connect and disconnect, during ON and OFF phases, a supply voltage to each winding on a PWM basis. The magnitude of the supply voltage and the temperature of the power chip vary. The microprocessor sends a digital control signal to the controller chip for gross control. The controller chip sends a PWM signal to the power chip for fine control. The power chip has pins for receiving the supply voltage, for sending a modulated signal to the controller chip; and for receiving the PWM signal from the controller chip. Circuitry in the power chip responds to the supply voltage to generate a first signal carrying analog information representing the magnitude of the power supply voltage, responds to the temperature of the power chip to generate a second signal carrying binary information corresponding to a thermal condition within the power chip, and responds to the first and second signals to generate a modulated signal which has a first characteristic carrying the analog information and a second characteristic carrying the binary information. Circuitry in the controller chip responds to the modulated signal to adjust the PWM signal to cause its ON phase to be substantially independent of the magnitude of the supply voltage, and demodulates the modulated signal to produce a warning signal and to send the warning signal to the microprocessor.
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